Omnidirectional, “360-degree,” or “3-dimensional” cameras are often used to capture spherical video footage. As the name implies, omnidirectional cameras may capture spherical video in every direction from a particular point of reference, such as a user wearing the omnidirectional camera or a particular object to which the omnidirectional camera is mounted, at a particular moment in time. To do so, conventional omnidirectional cameras typically include two or more separate camera units, with each having a respective field of view and being oriented to point in different directions. For example, a conventional omnidirectional camera may include two cameras orientated (position and direction) back-to-back, each recording video over a 180-degree field of view (when viewed from above the omnidirectional camera) corresponding to an approximate hemispherical shape and collectively over a 360-degree field of view corresponding to a spherical shape. After the video footage is recorded by each camera, image processing is applied to the separately recorded video footage to form a coalesced spherical video that represents spherical video footage of an event.
Often, when the spherical video is played back on a two-dimensional (flat) display screen, a user may interact with the spherical video via a user interface to pan the video to different portions of the spherical video. In other words, although the spherical video includes captured video in every direction around the omnidirectional camera, it is generally presented as two-dimensional equirectangular video frames that have a field of view associated with a single focal direction, which is a center point of an equirectangular video frame having a substantially narrower field of view than that of the overall spherical video itself. Often times, the playback utilizes a default focal direction corresponding to the orientation of the omnidirectional camera and the field of view associated with the default focal direction.
For example, an omnidirectional camera may be mounted to a helmet worn by a user engaged in an event for which the user desires to capture video footage, and the omnidirectional camera may include two camera units oriented back-to-back. The omnidirectional camera may be oriented such that a first camera unit has a focal direction directed forward such that it is pointing in the same direction as the user's eyes (i.e., the omnidirectional camera turns as the user's head turns up or down and/or to a left or right side), while the second camera unit has a focal direction that is rotated 180-degrees from the first camera unit. Thus, the focal direction and field of view of the omnidirectional camera may be locked to the user's head movements such that the captured spherical video is presented with the corresponding focal direction and field of view when played back.
As a result, the spherical video may be played back from a first-person perspective (of the user when the video footage was recorded) and may also include erratic movements depending on the user's overall motion during video recording. Thus, the field of view presented during playback corresponds to the user's head movements and changes in direction, and often deviates from the user's direction of travel. This conventional playback technique may result in causing valuable footage to be out of view during playback unless a user manually pans the spherical video to a region that is of interest. As a result, current omnidirectional camera systems and playback techniques have several drawbacks.